| Index: src/heap/store-buffer.cc
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| diff --git a/src/heap/store-buffer.cc b/src/heap/store-buffer.cc
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| index ffd5d96c5c663ce9f98fdc723352da07d209679c..45fc7a22f639c4ff18ad378259150b60c66538f5 100644
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| --- a/src/heap/store-buffer.cc
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| +++ b/src/heap/store-buffer.cc
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| @@ -85,7 +85,7 @@ void StoreBuffer::FlipStoreBuffers() {
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|    current_ = other;
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|    top_ = start_[current_];
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|  
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| -  if (!task_running_) {
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| +  if (!task_running_ && FLAG_concurrent_sweeping) {
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|      task_running_ = true;
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|      Task* task = new Task(heap_->isolate(), this);
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|      V8::GetCurrentPlatform()->CallOnBackgroundThread(
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| 
 |